3, 4-dichlorophenylsulfonyl tribromomethane



Patented Oct. 11, 1949 3,4 -DICHLOROPHENYLSULFONYL TRIBROMOMETHAN E W E Craig,

Drexel Hill,

Delaware Philadelphia, and William F. Hester, Pa., assignors to Rohm & Haas Company, Philadelphia, Pa.,

a corporation of No Drawing. Application August 7, 1947, Serial No. 767,314

1 Claim.

This invention concerns the chemic compound of the formula 3,4-Cl2CsI-l'3SO2CBI3. This compound has marked fungicidal properties and may be used in fungicidal compositions on plants.

A convenient method for the preparation of this new compound starts with oc-3,4-dlChI0- phenylsulionyl acetic acid. When this acid is converted to a salt and treated in alkaline solution with bromine or sodium hypobromite, there results a compound of the formula The reaction is carried out at temperatures between 0 and 40 0., preferably in aqueous solutions with sufiicient free alkali to maintain the reaction medium on the alkaline side throughout the reaction. Two equivalents of alkali are used up by decarboxylation.

Details of a typical preparation follow.

Two hundred parts by weight of sodium hydroxide was dissolved in enough water to give four thousand parts of solution. This was cooled to C., and thereto was added 315 parts of 3,4-Cl2C6H3SOzCH2COOI-I. When this acid had dissolved, the solution was cooled to 7 C. and 384 parts of bromine slowly added with stirring and cooling of the reaction mixture, which was then allowed to stand for about sixteen hours. The mixture was then stirred for an hour at room temperature. The white solid which had formed was separated by filtration, washed twice with water, and dried at 100 C. to give 334 parts by weight of a solid melting at 170173 C. Recrystallization from isopropanol of this material gave a white solid melting at 1'72174 C. The

analysis of the product agrees with that calculated for C12C6H3SO2CBI3.

From the alcohol a product may be recovered in small amount corresponding in composition lg) 3,4-Cl2Ca1-IsSO2CI-IBr2 and melting at 82-84 A solution of 3,4-Cl2CsI-I3SO2CBr3 was made in three times its volume of acetone, and the acetone solution was extended with water to ten thousand parts per million of the compound. This solution was toxic to Macrosporium sarcinaeforme Cav. and Sclerotim'a fructicola, when tested by the slide germination method (cf. J. Phytopathology 33, 354). At ten-fold dilution of the above solution, the growth of Sclerotinia was still prevented.

We claim:

A compound of the formula W E CRAIG. WILLIAM F. HESTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

